a special edition of "this week." Game changers. As the year draws to a close, those who made their mark in 2013. Fresh insights on a new pope. The tea party stars shaking up washington. The hacker who revealed america's secrets, raised fears of big brother. They thought that the bullet would silence us, but they failed. And the young girl who inspired us all. By defying fear. New, exclusive interviews. The game changers of 2013. They changed the world and they're right here this sunday morning. Hello again. I hope you're enjoying this holiday week. One we're marking with a special look back at people who broke through and made a big difference in 2013, our "this week" game changers. We've got some surprising revelations and brand-new interviews, starting with texas senator ted cruz. It's hard to remember a freshman senator stealing the spotlight so quickly and with such force. He stopped the government in its track for 16 days. To cheers from tea party activists. Jeers from democrats. But that's not slowing cruz a bit. He's setting his sights on a higher office. Abc's chief white house correspondent jonathan karl has his story. Reporter: When it comes to politics, you could say this has been the year of ted cruz. It's the government that needs more help. Reporter: Aside from the president, no one attracted more attention or more controversy. Cruz went from obscurity to leading presidential candidate in a political nanosecond. And a man at the center of the government shutdown ended 2013 as runner-up to the pope as "time"'s person of the year. This one ended up on the couch next to jay leno. I have been reading a lot about you lately. And they describe you as aggressive, arrogant and abrasive. Is that accurate? I'm trying to do my job. And, occasionally people don't like that. Reporter: Do you want people in washington to like you? You know, jon, what I want to do is I want to serve the texans. I want to do my job. Reporter: Do you care, does it bother you that a lot of people just don't like you? Nobody should be surprised if you're trying to change washington, that the washington establishment pushes back. Reporter: And push back they did. Just weeks after his swearing-in, cruz seemed to be off to a rough start. Quickly rubbing his new colleagues in senate the wrong way. Senator cruz has gone over the line. I'm not a sixth grader. Senator, I have been on this committee for 20 years. Reporter: Senator john mccain branded cruz and his fellow tea partyers wacko birds. An insult to be sure, but cruz didn't seem to mind. If standing for liberty and free market, that makes you a wacko, then I'm a very proud wacko bird. Reporter: A supporter everybody made a wacko bird hat that cruz proudly displays in his office. After obama met with senator republicans, cruz talked of working with the president I welcome the president coming to capitol hill to meet with us. I'm looking forward to do everything I can to work productively. To roll up our sleeves and get the economy growing again. Reporter: That didn't last long as cruz laid out the gold that would turn washington upside-down. Defunding obama care before agreeing to fund the government. At first, republican leaders rejected the idea. Our goal here is to cut spending, it's not to shut down the government. Reporter: But cruz refused to go along with the republican leadership. He gave an all-day, all-night speech. The second longest in the history of the senate. I intend to speak in support of defunding obamacare. Until I'm no longer able to stand. This grand experiment 3 1/2 years ago is quite simply not working. Reporter: He went on for more than 21 hours without sitting or even taking a bathroom break, filling time in some creative ways. Mike lee, I am your father. They said redneck rule number one, most things can be fixed with duct tape and extension cords. That's actually very true. I do not like green eggs and ham. Reporter: The speech made cruz a national figure a rallying point for those who agreed with him and those who didn't. Giving plenty of material for late-night comedians. The snooze of washington, d.C., Those whose name was ted cruz. Reporter: Cruz found his most receptive audience. At a mexican restaurant on capitol hill called tortilla coast. You mad a famous meeting right here in this restaurant. What was that like meeting with those house republicans? In a way they were looking to you as a leader. Well, we had lots of meetings throughout the year and throughout the shutdown as well. And nobody should be surprised that members of congress are talking to each other. It doesn't happen nearly enough. Reporter: But it's rare to see a senator to have the kind of influence that you had, a first-year senator, over the house. With respect, I actually don't think it was a case of my having influence. I think it's a case of a strategy you were putting forth. No, this is something that a lot of people came forward and agreed with. And at the end of the day, the conservatives who met here at tortilla coast, what we're trying to do is listen to the american people, who are saying this thing ain't working. Reporter: The house republicans went along with the cruz strategy and the government shut down for 16 days, in a move widely seen as a political disaster for republicans that accomplished nothing. The day republicans caved and congress voted to reopen the government, cruz declared victory. We saw the house of representatives take a courageous stand listening to the american people, that was a remarkable victory. Reporter: As the year draws to a close, republican leaders have made it clear, the strategy pushed by cruz and outside conservative groups was a total failure. Frankly, I think they've lost all credibility. You know, they pushed us into the slate to defund obamacare. One of these groups stood up and said, well, we never thought it would work. Are you kidding me!? Reporter: Ted cruz, the most high-profile tea party conservative in congress, again at tortilla coast, cruz reflected on all of that. When you think about the tradition of first-year senators, they tend to be seen, but not heard, you have heard a whirlwind for a first year as a u.S. Senator, does that surprise you? You're on "time's" magazine -- runner-up to the pope for person of the year. That was a very strange thing. This is a city where it's all politics all the time. And I'm trying to do my best not to pay attention to the politics, to focus on fixing the problems. Reporter: Really? I know that's hard to believe. Because no one in this town does that. This is a time for people to step up and do the right thing and that's wham trying to do. Reporter: You had a couple of months to think about this. Now that it's over in hind sight, are you prepared to say it was a mistake? I think it was absolutely a mistake for president obama and harry reid to force a government shutdown. Reporter: John boehner said that this was a republican shutdown. I understand in the media, jon, every day the media reported the republicans shut it down -- Reporter: The only reason this happened because you insisted that obamacare be defunded. As a condition of funding the government. If you took that away, there would be no shutdown. And you've got democrats in the middle of the shutdown, president obama called every senate republican to the white house, sat us in a room, and i called you to tell you, we're not going to compromise on anything. Repeatedly republicans were compromising, trying to find a middle ground. And repeatedly democrats said, no compromise, shut it down. Reporter: One of the odder signs of cruz's new celebrity is the new coloring book. This is the number one selling coloring book on amazon. Jon, if there a world is a crazy place, that is it. I had no idea. Reporter: I don't want to take the coloring book all that seriously, it does say in this coloring book, your filibuster was so important because americans believe obamacare is worse than any war. Let me ask you, jon, just for clarification, is this the first time that anyone's been on your show for a coloring book? Reporter: Obamacare is not worse than war? Of course not. Reporter: One more thing, when it comes to the year that was, feathers ruffled, the shutdown, the late-night jokes, cruz says he has no big regrets. For "this week," jonathan karl. Abc news, washington.

This transcript has been automatically generated and may not be 100% accurate.

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